netways-e.book Seite 2 Freitag, 28. November 2003 3:51 15 NetWAYS/ISDN This manual and the software it describes are protected by copyright. The manual and software as presented are the object of a license agreement and may be used only in accordance with the license conditions. The licensee bears all risk in regard to hazards and impairments of quality which may arise in connection with the use of this product.
netways-e.book Seite 3 Freitag, 28. November 2003 3:51 15 Contents 1 1.1 1.2 2 2.1 2.2 2.3 2.4 2.5 3 3.1 3.2 3.3 3.4 3.5 4 4.1 4.2 4.3 4.4 4.5 5 5.1 5.2 5.3 Welcome to NetWAYS/ISDN 5 Why NetWAYS/ISDN? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Package Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Installation and First Steps 12 System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
netways-e.book Seite 4 Freitag, 28. November 2003 3:51 15 Typographical Conventions The following typographic conventions and symbols are used in this manual to make reading easier and to emphasize important information. Highlighting The table below explains the highlighting conventions used in this manual. Highlighting Function Example: Quotation marks Keys, buttons, icons, “Start / Programs” or tabs, menus, comands “Enter” Capital letters Path and file names in running text DOKU\NETWAYS.
netways-e.book Seite 5 Freitag, 28. November 2003 3:51 15 Welcome to NetWAYS/ISDN 1 Welcome to NetWAYS/ISDN NetWAYS/ISDN integrates remote workstations and mobile computers in the company network. In this way all classic LAN applications can be used over ISDN: client/server applications, Internet applications, e-mail, database applications, and terminal emulation programs.
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netways-e.book Seite 8 Freitag, 28. November 2003 3:51 15 Cost Management Cost Management One of the primary objectives in designing NetWAYS/ISDN was to minimize the ISDN connection costs. NetWAYS/ISDN uses proven techniques optimized for ISDN to cut connection costs to the bare minimum. This means that remote access is as economical as possible. In “Short-Hold Mode”, the ISDN connection is cleared down whenever idle.
netways-e.book Seite 9 Freitag, 28. November 2003 3:51 15 Speed Speed With 64 kbit/s per channel, ISDN provides sufficient native bandwidth for today’s client/server applications. Thanks to on-the-fly data compression and header compression, NetWAYS/ISDN achieves a further performance boost. These techniques permit speeds of up to 240 kbit/s, depending on the type of data transported. Moreover, two B channels can also be bundled to increase bandwidth still further.
netways-e.book Seite 10 Freitag, 28. November 2003 3:51 15 Interoperability Interoperability At the LAN end, the AVM Access Server is an especially advantageous dial-in point for remote access with NetWAYS/ISDN. In addition, NetWAYS/ISDN guarantees interoperability with remote access servers that support the PPP over ISDN standard. NetWAYS/ISDN users will find this standard ensures convenient connections to Internet Service Providers.
netways-e.book Seite 11 Freitag, 28. November 2003 3:51 15 Package Contents 1.2 Package Contents The NetWAYS/ISDN package contains: 1 NetWAYS/ISDN v6.0 CD-ROM 1 NetWAYS/ISDN v6.0 manual If either of these components is missing, please contact your supplier. If the computer for which you have purchased the NetWAYS/ISDN license does not have a CD ROM drive for installation, you may copy the necessary software from the NetWAYS/ISDN CD to floppy disks for this non-commercial purpose.
netways-e.book Seite 12 Freitag, 28. November 2003 3:51 15 Installation and First Steps 2 Installation and First Steps This chapter describes how to install and remove and how to start and stop NetWAYS/ISDN. Furthermore, the section “Getting Started” on page 15 explains how you can set up a test connection to the AVM Data Call Center, and what to do to set up an Internet connection. 2.
netways-e.book Seite 13 Freitag, 28. November 2003 3:51 15 Remote Access Server Hardware and Software Remote Access Server Hardware and Software Windows XP, 2000, or NT server with the AVM Access Server and an AVM ISDN-Controller B1, T1, T1-B, C2 or C4 any remote access server that supports PPP over ISDN 2.2 Installing NetWAYS/ISDN To install NetWAYS/ISDN, proceed as follows: 1. Insert the NetWAYS/ISDN CD in your CD-ROM drive. The CD introduction starts automatically. 2.
netways-e.book Seite 14 Freitag, 28. November 2003 3:51 15 Default Configuration The NetWAYS/ISDN program files are then copied to your hard disk. In Windows XP, the installation process may be interrupted by an operating system warning that refers to the Windows logo test. Ignore this warning and continue the installation. 9. When the installation has been completed, restart your computer. When the computer has been restarted, NetWAYS/ISDN is ready to use.
netways-e.book Seite 15 Freitag, 28. November 2003 3:51 15 Getting Started Idle physical 50 seconds. connections are dropped after The logical connection is terminated at the same time. Channel bundling is set to “Manual”. Cost allocation is set to “Caller”. The CLI number (Caller ID) is not used for authentication. NetWAYS authenticates itself with the ADC using the user name “Gast”, and without a password. 2.
netways-e.book Seite 16 Freitag, 28. November 2003 3:51 15 First Connection: Testing TCP/IP First Connection: Testing TCP/IP To set up a connection to the ADC using the network protocol TCP/IP, perform the following steps: 1. Open the NetWAYS/ISDN window. 2. Select the call destination “Fast Internet over ISDN”. 3. Select the “Connect” command in the “File” menu.
netways-e.book Seite 17 Freitag, 28. November 2003 3:51 15 Going Online with NetWAYS/ISDN Local System Prerequisites When creating a call destination for your Internet Service Provider, please observe the following instructions: Deactivate the network protocol IPX/SPX in the NetWAYS/ISDN call destination settings. Set the delay before an idle physical connection is dropped to more than 10 seconds. At peak use times, dialing up the connection to an Internet Service Provider can take a while.
netways-e.book Seite 18 Freitag, 28. November 2003 3:51 15 Going Online with NetWAYS/ISDN 6. Enter the authentication information for your Internet access account. 7. Click “Next”, then “Finish” to complete the configuration. An icon representing the Internet connection now appears in the NetWAYS/ISDN window. Importing a VPN Connection Configuration Created with the AVM Access Server The AVM Access Server allows you to export the configuration data for a VPN user to a file.
netways-e.book Seite 19 Freitag, 28. November 2003 3:51 15 Removing NetWAYS/ISDN 2.5 Removing NetWAYS/ISDN To save all the settings you have configured in NetWAYS/ISDN, make a backup copy of all files in the program installation folder with the file name extensions .DAT and .IDX. After you have reinstalled the same version of NetWAYS/ISDN, simply copy these files back to the NetWAYS/ISDN installation folder. Your settings are then available once more.
netways-e.book Seite 20 Freitag, 28. November 2003 3:51 15 Remote Access with NetWAYS/ISDN 3 Remote Access with NetWAYS/ISDN This chapter explains the basic principles of NetWAYS/ISDN, and provides detailed information about the features, functions and configuration options. For complete information about individual commands and parameters, see the Online Help. 3.1 Throughput Optimization Each ISDN B channel permits data throughput of 64 kilobits per second.
netways-e.book Seite 21 Freitag, 28. November 2003 3:51 15 Channel Bundling Channel Bundling In addition to compression, NetWAYS/ISDN can also optimize throughput by using both ISDN B channels for the data connection. Channel bundling attains a bandwidth of 128 kbit/s (2 x 64 kbit/s). The following channel bundling options can be configured: Channel bundling setting Description None The connection is set up using only one B channel. Static The connection always uses two B channels.
netways-e.book Seite 22 Freitag, 28. November 2003 3:51 15 Physical Inactivity Timeout automatically dials up the connection. Thanks to the fast dial-up times in ISDN (1 to 2 seconds), this operation is hardly noticeable. The time before the idle physical connection is cleared down (the inactivity timeout) can be controlled either as a fixed delay setting, or by charge profiles.
netways-e.book Seite 23 Freitag, 28. November 2003 3:51 15 Logical Connection Timeout Predefined charge profiles are supplied with NetWAYS/ISDN for German rates. These profiles reflect the usual rates applied to Deutsche Telekom’s standard ISDN line offering. NetWAYS/ISDN also allows you to create your own charge profiles or edit an existing one to suit your requirements, by adding your national holidays for example.
netways-e.book Seite 24 Freitag, 28. November 2003 3:51 15 Filters and Spoofing Logical connection Physical connection No charges Data transmission Charges No charges Data transmission Physical connection Charges Tim e Inactivity Timeout Disconnect Timeout Physical and logical connection timeouts, with fixed inactivity timeout delay Filters and Spoofing Network clients, servers and applications exchange not only user data, but also network control information.
netways-e.book Seite 25 Freitag, 28. November 2003 3:51 15 Filters and Spoofing NetWAYS/ISDN provides the following filters for the IPX and IP protocols: SNMP SNMP (Simple Network Management Protocol) is a common protocol used to transport network management information. SNMP packets are used for centralized monitoring of network resources. These packets transport status and alarm messages from network components such as workstations, servers and routers. SNMP can be transported by IP and IPX packets.
netways-e.book Seite 26 Freitag, 28. November 2003 3:51 15 Filters and Spoofing Local Network (LAN) User data: Files, etc. User data: E-mail, etc. Network data packets: Watchdog, SPX, ARP, NetBIOS, SNMP and NCP Remote Access Server Filter and spoofing mechanisms AVM Access Server User data: E-mail, etc. User data: Files, etc. User data: Files, etc. ISDN User data: E-mail, etc. Remote computer with NetWAYS/ISDN NetWAYS/ISDN Filter and spoofing mechanisms User data: E-mail, etc.
netways-e.book Seite 27 Freitag, 28. November 2003 3:51 15 Filters and Spoofing PC are likewise acknowledged locally by NetWAYS/ISDN, and not sent over ISDN to the remote network. NCP spoofing NCP (NetWare Core Protocol) spoofing prevents NCP requests such as “Get Directory Path” or “End of Job” from being sent over ISDN. Such NCP requests are frequently generated by Windows applications opening a dialog to browse the file system, as when the command “File / Open” is selected in Microsoft Word for example.
netways-e.book Seite 28 Freitag, 28. November 2003 3:51 15 Call-back Options and Cost Allocation Call-back Options and Cost Allocation A classic use of NetWAYS/ISDN is to integrate telecommuters in a company LAN. Typically, the telecommuters’ ISDN costs for connections to the LAN are always borne by the same site—usually the company's main office. For this purpose NetWAYS/ISDN provides the “Call-back request” and “COSO” (Charge One Site Only) features for ISDN-optimized cost allocation and call-back.
netways-e.book Seite 29 Freitag, 28. November 2003 3:51 15 Call-back Options and Cost Allocation The COSO feature in NetWAYS/ISDN works as follows: When charge assignment is set to the default option “Caller”, the connection costs are borne by whichever site dials up the connection. Use this setting if the remote system does not support charge assignment. When charge assignment is set to “Local system”, all connections are charged to the local site.
netways-e.book Seite 30 Freitag, 28. November 2003 3:51 15 Leased Lines The following diagram illustrates the cost allocation function using the “remote system” setting.
netways-e.book Seite 31 Freitag, 28. November 2003 3:51 15 Security 3.3 Security In remote network access, it is very important to protect both the remote access server and the NetWAYS/ISDN computer against unauthorized access. NetWAYS/ISDN provides several security mechanisms for this purpose, which must also be supported by the remote access server. The following diagram illustrates the security checks that can be applied on a connection to a remote access server.
netways-e.book Seite 32 Freitag, 28. November 2003 3:51 15 User Name and Password Transmission of the caller’s number over the ISDN D channel (Calling Line Identification, or CLI) is an ISDN feature used by NetWAYS/ISDN for protection against unauthorized access and for charge assignment. In order for the “CLI” number check to function in NetWAYS/ISDN, the CLI feature must be activated for the ISDN line by the ISDN provider.
netways-e.book Seite 33 Freitag, 28. November 2003 3:51 15 Data Encryption Data Encryption Data packets can be sent in encrypted form to protect them against unauthorized access during transmission. Encryption is performed at the PPP level in accordance with the RFC standards. Because data compression is also performed at this level, the data can be first compressed and then encrypted. Encryption is performed using the Twofish algorithm, a symmetrical or “secret key” encryption technique.
netways-e.book Seite 34 Freitag, 28. November 2003 3:51 15 Internet Connections 3.4 Internet Connections For connections to the Internet, NetWAYS/ISDN also supports the economical AO/DI service and high-speed ADSL access. AO/DI allows you to maintain a permanent, economical connection to the Internet over the ISDN D channel. ADSL permits Internet access at significantly higher data speeds. IP masquerading and Short-Hold Mode provide additional security on connections to the Internet.
netways-e.book Seite 35 Freitag, 28. November 2003 3:51 15 IP Masquerading NetWAYS/ISDN supports the ADSL protocols PPP over Ethernet (PPPoE) and PPP over ATM (PPPoA). If FRITZ!Card DSL is used for the connection to the ADSL line, either of these protocols can be used. If the computer is connected to ADSL using an Ethernet adapter and an external ADSL modem, then only PPPoE can be used. NetWAYS/ISDN comes with two pre-configured locations for ADSL: “FRITZ!Card DSL” and “ADSL Modem PPPoE”.
netways-e.book Seite 36 Freitag, 28. November 2003 3:51 15 VPN Connections 3.5 VPN Connections NetWAYS/ISDN allows you to set up Virtual Private Network (VPN) connections. VPN connections are an economical way to connect remote PCs to the company LAN. Until recently, remote systems were usually interconnected using direct dial-up or leased line connections over public telecommunication networks, such as ISDN or GSM. However, the costs for direct dial-in increase with the distance to be bridged.
netways-e.book Seite 37 Freitag, 28. November 2003 3:51 15 VPNs in NetWAYS/ISDN VPNs in NetWAYS/ISDN The term VPN refers simply to a private link carried over a public infrastructure. Which techniques are used to accomplish this is not specified. NetWAYS/ISDN sets up its VPN links over existing Internet connections, taking advantage of the Internet Service Provider’s infrastructure.
netways-e.book Seite 38 Freitag, 28. November 2003 3:51 15 The VPN Protocol IPsec Authenticity When a connection is opened, the communicating parties must be identified to ensure that all data comes from the authentic source, and is not simply being replayed by an interceptor, for example. Integrity The VPN must ensure that data cannot be modified by third parties (as in “man-in-the-middle” attacks) on its way through Internet.
netways-e.book Seite 39 Freitag, 28. November 2003 3:51 15 The VPN Protocol IPsec Original packet IP header Payload data IPsec-encapsulated packet New IP header IPsec IP header Possibly encrypted pa yload data Original packet and IPsec encapsulated packet with new IP header The illustration below shows a sample VPN connection in Tunnel Mode. Here a remote stand-alone computer is connected to the local company network. Com pany netw ork Netw ork address: 172.16.0.
netways-e.book Seite 40 Freitag, 28. November 2003 3:51 15 The VPN Protocol IPsec in the LAN using an internal IP address. The AVM Access Server also provides the LAN with its gateway to the Internet. Remote Computer with NetWAYS/ISDN When the VPN connection is active, the remote standalone computer also has two IP addresses: its official IP address that is valid in the Internet, and its IP address in the virtual private network.
netways-e.book Seite 41 Freitag, 28. November 2003 3:51 15 The IPsec Transport Protocols The diagram below shows sample IP addresses for source and destination in the two packet headers: IP address of the recipient: 172.16.0.1 IP address of the sender: 172.16.0.10 O riginal pa cket Payload data IP header N ew IP header IPsec Payload data (possibly encrypted) IP header IPsec-encapsulated packet with new IP header in Tunnel Mode IP address of the recipient: 193.96.242.
netways-e.book Seite 42 Freitag, 28. November 2003 3:51 15 Negotiation Properties of the Encapsulating Security Payload (ESP) Encrypts the user data payload. In Tunnel Mode, the IP header is also encrypted. The symmetrical encryption methods available include DES, 3DES, AES and others. Authenticates the source of the payload data: ESP includes a mechanism that allows the recipient to verify whether the source of the data is authentic.
netways-e.book Seite 43 Freitag, 28. November 2003 3:51 15 Negotiation the duration of validity, or “lifetime”, of the SA SAs have a limited period of validity. When the lifetime of an SA has elapsed, a new SA must be negotiated. A separate SA is negotiated for each direction of communication. The SAs are stored in the security association database. IKE negotiation takes place in two phases. IKE Phase 1 The purpose of IKE Phase 1 is to negotiate an SA to provide secure communication during IKE Phase 2.
netways-e.book Seite 44 Freitag, 28. November 2003 3:51 15 Asymmetrical Encryption Techniques IKE Phase 2 The goal of IKE Phase 2 is to negotiate the SAs for the encryption of actual user data. This negotiation is itself encrypted based on the SA that was negotiated in Phase 1.
netways-e.book Seite 45 Freitag, 28. November 2003 3:51 15 Compression Techniques (IPComp) the author’s public key, and the resulting hash value compared with a locally calculated hash of the message as received. If the values match, then the signer must have possessed the corresponding secret key, and message can hence be considered authentic.
netways-e.book Seite 46 Freitag, 28. November 2003 3:51 15 NetWAYS/ISDN for Administrators 4 NetWAYS/ISDN for Administrators This section provides the network administrator with additional information about the functions used to install, configure and manage NetWAYS/ISDN according to your individual requirements. 4.
netways-e.book Seite 47 Freitag, 28. November 2003 3:51 15 Installing Pre-configured Call Destinations and Locations Please note that the configuration values in the following description are merely examples. The SETUP.CFG file should contain the following information: CDKey_NETWAYS=XXXXXXXXXXXXXXXX This is the Product Identification Code (PIC). All letters are uppercase; dots, hyphens and slashes are omitted.
netways-e.book Seite 48 Freitag, 28. November 2003 3:51 15 Installing Pre-configured Profiles TARGETU.IDX Charge profile assignments to call destinations and locations: TTIMER.DAT TTIMERCE.IDX TTIMERID.IDX TTIMERL.IDX Location files: LOCATION.DAT LOCATIONI.IDX LOCATION.IDX In order for your call destinations and locations to be copied in new installations, these files must be placed in the NetWAYS/ISDN installation folder.
netways-e.book Seite 49 Freitag, 28. November 2003 3:51 15 Locking the Settings Files containing the charge profiles: CPROFILE.DAT CPROFILE.IDX 4.2 Locking the Settings The administrator can set a password to protect the preconfigured locations, call destinations, profiles and holiday list against changes by the NetWAYS/ISDN user. Once locked, the settings can only be changed by entering a password.
netways-e.book Seite 50 Freitag, 28. November 2003 3:51 15 Starting and Ending NetWAYS/ISDN Manually The NetWAYS/ISDN user interface is separate from the service. If you want the NetWAYS/ISDN window to be opened when Windows starts, copy a shortcut to NetWAYS/ISDN to the “Startup” folder. Starting and Ending NetWAYS/ISDN Manually To start NetWAYS/ISDN manually, select the command “Programs / NetWAYS/ISDN / NetWAYS/ISDN” in the Windows Start menu. The NetWAYS/ISDN window appears.
netways-e.book Seite 51 Freitag, 28. November 2003 3:51 15 The NetWAYS/ISDN API 4.4 The NetWAYS/ISDN API NetWAYS/ISDN provides a number of programming interfaces to allow custom applications to control routing, remote access and data encryption. Routing and Remote Access API AVM’s routing and remote access API is a program interface which allows NetWAYS/ISDN to be controlled by external software. This API permits other tasks and routines to use NetWAYS/ISDN commands for automatic operation.
netways-e.book Seite 52 Freitag, 28. November 2003 3:51 15 Supported Standards 4.5 Supported Standards The protocols PPP over ISDN and IPsec are based on internationally recognized, open internetworking standards. These standards are defined and described in RFCs (Requests for Comments), the Internet standardization documents. To be compatible with NetWAYS/ISDN’s features, remote systems must provide support for the corresponding RFCs. The following two tables list the RFCs implemented in NetWAYS/ISDN.
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netways-e.book Seite 54 Freitag, 28. November 2003 3:51 15 Information, Updates and Support 5 Information, Updates and Support AVM provides numerous sources of information to assist you in your day-to-day work with NetWAYS/ISDN. If you need help in solving problems that may occur, you can also get in touch with AVM Support. 5.
netways-e.book Seite 55 Freitag, 28. November 2003 3:51 15 Updates 5.2 Updates The latest software updates for NetWAYS/ISDN are available free of charge from AVM’s web site, or from the AVM Data Call Center. Internet To download updates over the Internet, please visit: www.avm.de/en/download You can also download software updates from AVM’s FTP server. Click the ”FTP Server” link in the download area, or see: www.avm.
netways-e.book Seite 56 Freitag, 28. November 2003 3:51 15 Support by Fax 1. Enter AVM’s Internet addresses: http://www.avm.de/en/service 2. On this page, select “NetWAYS/ISDN” in the list of “Software” products. 3. Then select the area in which you encountered the problem. An e-mail form appears. 4. Fill out the form and send it to AVM support by clicking the “Send” button.
netways-e.book Seite 57 Freitag, 28. November 2003 3:51 15 Support by Fax Is your ISDN-Controller connected to a PBX extension? Are you able to dial up a test connection to the AVM Data Call Center (ADC) using the pre-configured call destination “Fast Internet over ISDN”? At what point in the installation procedure or in the program does the error occur? What is the exact wording of the message? Once you have gathered this information, you are ready to contact AVM Support.
netways-e.book Seite 58 Freitag, 28. November 2003 3:51 15 Glossary ADSL (Asymmetric Digital Subscriber Line) ADSL is a communication technology that permits Internet access with high bandwidth over ordinary telephone cables. Data communication takes place at up to 6 Mbit/s downstream (that is, from the Internet to the user) and up to 640 kbit/s upstream. Other telecommunication services and dial-up connections to other subscribers are not possible over ADSL.
netways-e.book Seite 59 Freitag, 28. November 2003 3:51 15 incurred. AO/DI dynamically enables one or more B channels (Dynamic ISDN) depending on the amount of data to be transmitted. ARP (Address Resolution Protocol) The Address Resolution Protocol, or ARP, is part of the TCP/IP protocol suite. ARP is used dynamically to obtain the Ethernet hardware address (called the MAC address) of the interface that corresponds to a given IP address.
netways-e.book Seite 60 Freitag, 28. November 2003 3:51 15 authentication, the name and password assigned by the remote administrator must be entered as well. Obtain this information from the administrator of the remote site. B channel An ISDN basic access consists of two B channels and one D channel. The B channels are used to transport user data. They allow transmission at a rate of 64 kbit/s. B channels can be bundled to accelerate transmission.
netways-e.book Seite 61 Freitag, 28. November 2003 3:51 15 Client A client is a computer in a network that requests services from another system, such as access to files or information from databases. COMMON-ISDN-API (CAPI) CAPI is a standardized, manufacturer-independent interface between PC ISDN adapters and ISDN applications. The driver software for AVM ISDN-Controllers provides the CAPI interface throughout the system.
netways-e.book Seite 62 Freitag, 28. November 2003 3:51 15 Hash algorithm A hash algorithm is a function that yields a short value that is practically unique for a given input. The value of the hash is also called a “digest” of the input. One-way hash algorithms are used in cryptography to create digital signatures for authentication. Characteristics of one-way hash algorithms: – The input data can be of any length. – The output is generally of a fixed length.
netways-e.book Seite 63 Freitag, 28. November 2003 3:51 15 frame check sequence (FCS), and the end-of-frame flag. HDLC is used in full-duplex mode, and provides for the acknowledgment of several frames at a time (usually eight). The number of frames transmitted before acknowledgment is called the window size. Header Data packets are generally transmitted beginning with a header which contains the source and destination addresses and identifies the protocol used to interpret the packet.
netways-e.book Seite 64 Freitag, 28. November 2003 3:51 15 IP address Addressing is one of the main functions of the Internet Protocol (IP). Addresses in IP version 4 are 32-bit numbers, which can be written as four bytes in decimal, octal or hexadecimal notation. In the NetWAYS/ISDN configuration, “dotted-decimal” notation is used: The four bytes of an address are represented by decimal numbers separated by dots.
netways-e.book Seite 65 Freitag, 28. November 2003 3:51 15 Class A addresses consist of a one-byte network address and a three-byte host address: X._._._ Network address Host address Class A addresses Example: 88.120.5.120 (88 is the network address, 120.5.120 is the host address). Class B addresses consist of a two-byte network address and a two-byte host address: X.X._._ Network address Host address Class B addresses Example: 130.6.2.130 (130.6 is the network address, 2.130 is the host address).
netways-e.book Seite 66 Freitag, 28. November 2003 3:51 15 RFC 1918 (Address Allocation for Private Internets) reserves the following parts of the IP address space for use in private networks: 10.0.0.0 - 10.255.255.255 (10/8 prefix) 172.16.0.0 - 172.31.255.255 (172.16/12 prefix) 192.168.0.0 - 192.168.255.255 (192.168/16 prefix) IP masquerading Also known as Network Address Translation, or NAT.
netways-e.book Seite 67 Freitag, 28. November 2003 3:51 15 Keep-alive packets Keep-alive packets are sent periodically throughout the network to verify whether a client is still active. If the sending station receives no response, it clears down the logical connection. LAN (Local Area Network) A computer network limited to a given location, such as a company site or a government agency’s office building.
netways-e.book Seite 68 Freitag, 28. November 2003 3:51 15 These connection parameters are valid for the duration of a logical ISDN connection. These parameters include the network protocols used, the authentication requirements, spoofing mechanisms and channel bundling. Depending on the configuration, the logical ISDN connection will be cleared together with the physical connection or, if so negotiated with the remote site, remain valid even after the physical connection is no longer active.
netways-e.book Seite 69 Freitag, 28. November 2003 3:51 15 PAP (Password Authentication Protocol) One of the two authentication protocols in the PPP suite. A name and password for the remote system must be configured on the system that requests authentication. The remote system must be configured to present the same name and password. In PAP authentication, the name and password are sent unencrypted, and the authenticating system simply compares them with its settings.
netways-e.book Seite 70 Freitag, 28. November 2003 3:51 15 structure of data transport for a variety of networks. These standards are primarily intended to provide interoperability, ensuring that different manufacturers’ devices with different sets of features can communicate by a uniform method. PPP over ISDN is specified in RFC 1618. Ports TCP and UDP packet headers provide port numbers for source and destination, in addition to the IP addresses.
netways-e.book Seite 71 Freitag, 28. November 2003 3:51 15 SMTP (Simple Mail Transfer Protocol) SMTP is a standard protocol for exchanging e-mail between computers. SMTP implementations listen on TCP port 25. The protocol structure is simple, supporting only e-mail transmission over a data network. SMTP is defined in RFC 821. Spoofing “Spoofing” in data communication means to send data with a false source address, pretending to be from a different system.
netways-e.book Seite 72 Freitag, 28. November 2003 3:51 15 SPX (Sequenced Packet Exchange) A protocol that enables two workstations or applications to communicate over a network. SPX uses the NetWare protocol IPX for addressing. SPX uses NetWare IPX to transmit data, but controls the receipt and the order of messages in the packet stream. TCP (Transmission Control Protocol) TCP is a connection-oriented protocol for use over packet-oriented networks.
netways-e.book Seite 73 Freitag, 28. November 2003 3:51 15 Remote networks “Destination/Remote networks” is used as a collective concept designating Internet connections and connections to remote networks.
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